Morphological traits and environmental preferences of the Blunt-headed tree snake Imantodes cenchoa: the effects of sex and ontogeny

Abstract

Understanding morphological traits and environmental preferences within a population is essential to comprehend the relationship of species with their environment and to develop useful conservation strategies. This is especially important for secretive species such as arboreal snakes. Our study assessed how morphological variation in sex and age classes influenced environmental preferences in the Blunt-headed tree snake Imantodes cenchoa in Los Tuxtlas, Veracruz, Mexico. We used data from 249 individuals, consisting of 143 adults, 47 juveniles, and 59 hatchlings. We found significant linear relationships of snout-vent length and body mass with elevation and humidity. Environmental preferences did not differ between sexes, but elevation, humidity and temperature are differently selected by age classes. The greater tolerance of adults to environmental conditions allowed them to expand their habitat to places where they can find more food and shelter. In contrast, less tolerant hatchlings and juveniles benefited from vegetated, humid locations at lower elevation sites where food and shelter remain available during a longer period of the year. Our findings are relevant for the management and conservation of this species, listed as “with special protection” by Mexican Law, since environmental preferences are very restricted in hatchlings, a vital stage for the maintenance of the population. Efforts preserving lower sites, in constant threat by cattle breeders in the area, will preserve both sexes and all three age categories.